Just as the announcer yells "Go", press Boost. If done correctly, you will get a huge boost which propels you to the middle of the field in a flash. It may be difficult to time this correctly without practicing. Try shutting your eyes and just listening.
Game Shark Codes
Master Code (Must Be On) 0E3C7DF2 1853E59EEE861492 BCCA2B1A
All Weapons Available DEA4B576 C3989A82
Always Have Weapons FE9A74EA BCA99B84
Infinite Shield FE9A74F6 BCA99B84
Turbo Mode FE9A74F2 BCA99B84
Retro Planes FE9A74E6 BCA99B84
Infinite Proton Cannon FE9A6BFE BCA99B84
Game Time is Always 00:00 CEA4A630 BCA99B83
Unlock All Leagues DEA4B572 BCA98A82
Unlock All Teams/Vehicles DEA4A63E BCA99A82
Unlock Zone/Time Trial Mode DEA4A6CE BCA99B86
Unlock All Challenges DEA4A6C6 BBA89A82CEA4A6C2 BBA89A82
All Golds All Challenges DEA4A60E BBA89A82CEA4A60A BBA89A82